1. Field of the Invention
This invention relates to means and method for providing a temperature profile in a billet of solid metal. In one aspect, the invention relates to apparatus and method for providing and continuously monitoring and controlling a tapered temperature profile in a billet of aluminum or aluminum alloy for the purpose of efficient forming by extrusion.
2. Background Information
Commercial production for forming aluminum by extrusion recognizes the advantages of induction heating. Induction heaters were first introduced into aluminum extrusion processes to speed up the heating cycle. The induction heater induces heating currents in the billet by a flux field generated around the induction coil. The coil of an electrical conductor is impressed with an alternating voltage to generate the electromagnetic flux field. When conductive billet material is placed inside the coil, eddy currents are generated within the billet and are converted into heat energy. Induction heaters provide advantages of minimum start-up time, fast heating, low maintenance cost, reduced manpower, smaller shop floor space, and increased operator comfort.